1. Symptoms: Symptoms begin to appear as the fruit matures and the storage period continues to develop. Most of the lesions occur near the concave part, but less near the fruit shoulder. The flesh under the peel of the diseased department first developed lesions, and the skin of the disease appeared a circular spot centered on the lenticels. This spot is dark green on green or yellow varieties, dark red on red varieties, and slightly sunken. In the late stage, the flesh shrinks and the epidermis is necrotic, and the brown spots of the depression appear, which are 2-3 mm deep and have a bitter taste. There are usually 3 to 5 lesions on the diseased fruit, and 60-80 in the weight, spread over the fruit surface.
2. Causes: Apple bitter pox is mainly caused by the physiological calcium deficiency of the tree. The pruning is too heavy, the partial application, the late application of nitrogen fertilizer, the excessive growth of the tree and the poor orchard of the orchard are serious. The fruit has a large rainfall during the growing season, and too much watering is easy to aggravate the disease.
3. Control methods: First, strengthen cultivation management, rationally pruning, increase the application of farmyard manure, strictly prevent partial application and late application of nitrogen fertilizer, maintain a moderate tree to balance growth and development; at the same time pay attention to rainy season drainage, reasonable irrigation to prevent excessive ammonia nitrogen accumulation. The second is to increase the application of calcium fertilizer: the application of bio-organic active calcium in spring or autumn soil. About 30 days after apple Xiehua, every 15-20 days, spray 0.3% calcium nitrate solution until 20 days before fruit picking, the control effect is better. (Note that it is prone to phytotoxicity on the leaves when the temperature is high.) It is best to use bio-organic active calcium when applying the base fertilizer in autumn. The third is to strengthen the management of storage period: before the apples are put into storage, they should use 2%-8% calcium chloride or calcium nitrate solution to soak the fruit.
2. Causes: Apple bitter pox is mainly caused by the physiological calcium deficiency of the tree. The pruning is too heavy, the partial application, the late application of nitrogen fertilizer, the excessive growth of the tree and the poor orchard of the orchard are serious. The fruit has a large rainfall during the growing season, and too much watering is easy to aggravate the disease.
3. Control methods: First, strengthen cultivation management, rationally pruning, increase the application of farmyard manure, strictly prevent partial application and late application of nitrogen fertilizer, maintain a moderate tree to balance growth and development; at the same time pay attention to rainy season drainage, reasonable irrigation to prevent excessive ammonia nitrogen accumulation. The second is to increase the application of calcium fertilizer: the application of bio-organic active calcium in spring or autumn soil. About 30 days after apple Xiehua, every 15-20 days, spray 0.3% calcium nitrate solution until 20 days before fruit picking, the control effect is better. (Note that it is prone to phytotoxicity on the leaves when the temperature is high.) It is best to use bio-organic active calcium when applying the base fertilizer in autumn. The third is to strengthen the management of storage period: before the apples are put into storage, they should use 2%-8% calcium chloride or calcium nitrate solution to soak the fruit.
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